Time-resolved thermoelectrical effect in Sm0.56Sr0.44MnO3 perovskite

Sm0.56Sr0.44MnO3 CMR-manganite with perovskite structure has been studied u sing the time-resolved transient thermoelectric effect and heat capacity me asurements. It was observed that the Seebeck voltage shows an electron-like behavior in the temperature range 50-300 K except for a narrow interval in the vicinity of the Curie point. The transition into the metallic-like fer romagnetic state is not accompanied by an appreciable anomaly of the heat c apacity, it is argued that the electrical conductivity arises by the holes moving in a 2p-band of oxygen as well as by electrons in a 3d-impurity band . Arguments are given in favor of a short-range charge ordering in a wide t emperature interval above T-C. (C) 2000 Elsevier Science B.V. All rights re served.